I don't buy it. That squirrel is in suspiciously sharp focus, while the intended subjects are out of focus. When you set up a shot with the self timer, don't you first focus on the spot that you want to be in sharp focus? Ie, focus on the place that you are about to pose? Even with autofocus, you set up the shot first, and then run into the picture. I think they had their friend take the squirrel shot deliberately while they hung out in the background pretending it was supposed to be a shot of them.
It does look suspicious, but I recently took a bunch of auto focus shots of some ducks laying in tall grass (in wildlife shots thread) and a few of the shots had a long blade of grass in the way and the camera focused on the grass and the ducks were out of focus, just like the couple in the pic.